1. Technical Field
This disclosure generally relates to combination headsets containing speakers and microphones.
2. Description of the Related Art
Over a relatively short period of time, the cellular telephone has grown from a dedicated communication device to a multipurpose device having a surprising number of functions controlled using an architecture and processor closely resembling a dedicated computing device—giving birth to the term “smartphone.” Current smartphones have either a tip-ring-sleeve (referred to as a “TRS” jack) or a tip-ring-ring-sleeve (referred to as a “TRRS” jack) to accommodate audio input and/or audio output using external devices other than the speaker(s) and microphone(s) integrated into the body of the smartphone. These TRS and TRRS jacks are generally provided as either a 2.5 mm diameter or a 3.5 mm diameter female jack placed in an accessible area on an exterior surface of the smartphone body.
Although the TRRS jack is intended to provide two speaker circuits and one microphone circuit, additional functionality may be gleaned from the jack by configuring the smartphone hardware or operating system to recognize various signals transmitted to the operating system via the TRRS jack. Such hardware or operating system modifications are frequently device or platform specific and are somewhat limited in applicability by the sheer number and variety of smartphones on the market.
One popular smartphone feature is push-to-talk functionality. When using a push-to-talk mode, the smartphone user provides an input to the smartphone to place the smartphone in transmit or broadcast mode where the microphone is enabled. Transmit or broadcast mode is exited or ended when the smartphone user provides a second input to the smartphone indicating the termination of transmit or broadcast mode.
Push-to-talk functionality may be provided by adding conductors to the traditional tip-ring-ring-sleeve connector (e.g. a tip-ring-ring-ring-sleeve or TRRRS plug and jack). The added conductors provide one or more additional signal paths to the smartphone, which when coupled with appropriate changes to the smartphone operating system or software may be used to enter and exit a push-to-talk mode. Such added conductors require modification to smartphone components such as the jack which must be altered to accommodate the extra conductor on the TRRRS plug. Additionally, smartphone software or firmware may require modification or updating to support PTT functionality based on a modified TRRRS jack. Such modifications may be costly and inefficient, particularly when manufacturers resort to the use of customized or proprietary algorithms to facilitate PTT functionality.
Thus, hardware capable of providing push-to-talk functionality while reducing or eliminating the need to modify or customize smartphone hardware, software or firmware is desirable.